Method of cleaning streets



April l, 1941.

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METHOD OF CLEANING STREETS Filed May 12, 1938 5 Sheets-Sheet 3 /09Eon/41o Cfwfwrfmms QM LA @a y April 1, 1941. R. c. EvANs IETHOD OFCLEANING STREETS Filed May 12, 193e 5 Sheets-Shet 4 .FE '571-' @oA/LoClewwrfvaws.

April 1,1941. R,YC EVANS 2,236,813

METHOD OF CLEANING STREETS Filed May 12, 1938 5 Sheets-Sheet 5POA/,9.1.0 (2EME/vr .ZT/Amr.

Patented Apr. 1, 1941 'UNITED STTES PTENT OFFICE METHOD OF CLEANINGSTREETS Ronald Clement Evans'. Elgin, Ill., assigner to Elgin SweeperCompany, Elgin, Ill., a corporation of Illinois Application May 12,1938, Serial No. 207,443

1 Claim. (Cl. 15-269) This invention relates to street sweepingapparatus, and more particularly to a novel method and means forcleaning. streets.

The sub-ject matter hereof is related to that of my copendingapplications Serial Nos. 207,445,

207,446, and 216,740, the first two of which were filed on May l2, 1938,and the latter of which was filed on June 30, 1938.

Many forms of street sweeping apparatus have been employed in the pastfor cleaning streets and other surfaces to be swept. The different formsof sweeping-apparatus may be roughly classiiied as caterpillar brushsweepers, rotary brush sweepers, and combined rotary brush and conveyorsweepers. design of any of these sweepers lies in the fact The greatestdiiiiculty in the .f

that a sweeping apparatus which is particularly f well suited forsweeping dirt and other finely `divided debris has not in the past beenparticularly efficient in sweeping leaves, twigs, stones,

refuse, and other similar forms of debris; while sweeping apparatuswhich has been designed to sweep leaves and rther similar debrisefciently has not been particularly well suited for sweeping dirt andfinely divided debris. that the reason for this lies in the fact that anerhcient dirt sweeper requires a pick-up plate or drag plate disposed infront of the brush with its bottom edge very close to the surface beingswep-t, while an eicicnt sweeping apparatus for picking up leaves andthe like requires some means which will permit the leaves to pass to thebrush. In the first instance referred to above, the leaves are pushedahead of the sweeping apparatus and for that reason do notcome intocontact with the sweeping brush. Where the pick-up plate or drag plateis high enough to permit leaves to pass thereunder, the sweepingapparatus throws the dirt underneath the pick-up or drag plate and forthat reascn it is not swept up.

It is an object of the present invention to provide a novel method andmeans for sweep- .ing streets and the like which is efficient in piel:-

is to provide a novel method of accumulating4 and picking up debris.

It is believed i;

f `Another and still further object of this invention is to provide anovel method of segregating deb-ris into two classes and for contnuallysweeping one of said segregated classes of debris, but onlyintermittently sweeping ,said other segregated class of debris, saidsecond class of debris being pushed ahead of the sweeping apparatusduring the interval when it is not being swept.

' The novel features which I believe to be characteristic of myinvention are set forthwith particularity in the appended claim. Myinvention itself, however, both as to its organization and method ofoperation, together with further objects and advantages thereof may bestbe understood by'reference to the following description taken inconnection with the accompanying drawings in which:

Figure 1 is a side elevational view of a street sweeping apparatusemploying a caterpillar brush and a periodically oscillated drag plate;

Figure 2 is an enlarged fragmentary elevational view illustrating thelower endV of the caterpillar brush assembly and the drag plate whichcooperates therewith;

'Figure 3 is a greatly enlarged cross-sectional View of the drag plateand drag plate mounting of the sweeping apparatus;

Figure 4 is an enlarged cross-sectional end view of the drag plate anddrag plate mounting of the sweeping apparatus;

Figure 5 is a 'fragmentary bottom view of one side of the drag plate anddrag plate mounting;

Figure 6 is an enlarged fragmentary elevational view showing the dragplate carriage in its lower position and the drag plate being rockedupwardly as it passes over a large boulder;

Figure '7 is a view similar to Figure 6 but shows the drag platecarriage in its'upper position;

Figure 8 illustrates a different form of sweeping apparatus which iscapable of carrying out the novel method of the present invention; and

Figure 9 is a still further apparatus capable of carrying out the novelmethod of the present invention.

The sweeping apparatus illustrated in Figure 1 of the drawings is astreet sweeper of the caterpillar brush type. The sweeping elements ofthis apparatus together with their associated elements are mounted on amotor driven vehicle I0, the principal component parts of the completeapparatus being a caterpillar brush assembly ll, a dirt and debrisstorage hopper I2, and a chassis I3 having a rear mounted motor I4thereon (the motor being diagrammatically indicated by showing thecustomary hood enclosing the same). The chassis I3 includes a pair offront wheels I5 mounted on a Xed axle (not shown) and a pair of rearwheels I6 which are preferably mounted closely together on a pivotallymounted steering assembly I1. Steering assembly I1 is connected throughany suitable connecting mechanism to a steering wheel disposed in thedrivers compartment or cab I8.

To enhance the general appearance of the vehicle I0 and to protect thesweeping apparatus from the elements, a body I9 is provided which formsa continuation of cab I8 and which may be given any shape which willfurther enhance the general appearance of the vehicle. In the upperforward wall of the body I9, a relatively large transverse opening isprovided to permit access to the upper portion of the caterpillar brushassembly II. This transverse opening in the upper forward wall of bodyI9 is closed by a sliding cover 29 which is held in desired position bya pair of flange members 2| welded or otherwise suitably secured to thetop of body I9, the anges 2I being so arranged as to permit transversesliding movement of the cover 20.

The dirt and debris collecting hopper I2 is situated at the extremeforward end of the vehicle I0 and communicates directly with the upperportion of the brush assembly II. Hopper I2 is de signed to receive dirtand debris carried upwardly thereto by the sweeping apparatus and tostore the same until it is desired to empty the hopper I2. The lower endwall 22 of the dirt and debris collecting hopper I2 is pivotally mountedto the end of chassis I3 by a pair of hook shaped arms 23 which arepivotally secured to the horizontal frame members of the chassis I3 asat 24.

In order to hold the end wall 22 of hopper I2 in its closed position soas to preventescape of dirt and debris from the hopper, a flexible cableor chain 25 is employed to hold end wall 22 in place. Chain 25 isconnected at one end to end wall 22, is then passed over asheave 23secured to the side wall of the body I9, and is connected nally at itsopposite end to a dump lever 21. The dump lever 21 is pivotally mountedon the body I9 as at 28, its downward angular movement being limited bya suitable stop means (not shown) to the position shown in Figure 1. Inthis position the lever is in an overcenter position which automaticallylocks the end wall in its closed position. When dump lever 21 is movedupwardly and forwardly, the forward movement of the iiexible cable orchain 25 permits the end wall 22 to open by virtue of its own weight.

The caterpillar brush assembly II includes in general a caterpillarbrush 29, and a caterpillar brush housing 30 composed of an upperstationary housing portion 3l and a lower movable housing portion 32arranged for limited angular movement about a transverse axis. Morespecically, lower housing portion 32 is hinged to and supported by upperhousing portion 3l as at 33. The rear wall 34 of housing portion 32 ispreferably given a segmental cylindrical curvature, and the lower end 35of the top wall of the upper housing portion 3I is similarly curved butarranged to permit the lower housing member 32 to be telescopedthereover. The side walls of lower housing member 32 overlap the sidewalls of upper housing member 3| even when the former are in theirlowermost position. This substantially complete telescopic engagement ofthe lower housing member 32 with the upper housing member 3l permits theformer to be raised and lowered without any substantial interferencefrom the latter.

In order to permit ready accessibility to the caterpillar brush 29 torepair or replace a portion thereof, the rear wall 34 includes apivotally mounted panel 36 which preferably extends over a major portionof the rear wall 34.

The caterpillar brush assembly I I also includes a pair of dirt shoes 31carried on the lower housing portion 32 by arms 38, the latter beingpivotally connected to shoes 31 as well as to the housing portion 32.Dirt shoes 31 are in the form of runners which ride along the streetsurface, the forward and rear ends 39 and 40 being turned up for thatpurpose. These shoes prevent dirt and other debris from being thrown outthe sides of the sweeping apparatus. A stop block 4I on each side ofhousing portion 32 engages the arms 33 when the housing portion 32 israised and this carries the shoes 31 up with it. The general4 andspecific nature of dirt shoes 31 is described in claims in my copendingapplication Serial No. 207,446, led May 12, 1938, and assigned to thesame assignee as the present invention.

In order to provide continuous and efficient.

sweeping irrespective of ripples and the like in the street surface, aiioating mount 42 is provided for caterpillar brush 29. This floatingmount has the effect of permitting the lower end of the caterpillarbrush 29 to float on the surface being swept. The novel features of thisfloating mount are described and claimed in my aforesaid copendingapplication.

More specifically the caterpillar brush floating mount 42 comprises apair of tracks 43 and 44 which are mounted in parallel spacedrelationship on both sides of the lower housing portion 32. The tracks43 and 44 may be provided by employing offset ange members which arewelded or otherwise suitably secured to the sides of housing portion 32.Portions of the housing wall between the complementary track members 43and 44 are cut away as at 45 and 46 to permit free movement of thecaterpillar brush supporting means which extends therethrough. Acaterpillar brush supporting plate 41 having small wheels or rollers 48and 49 is disposed between each pair of complementary tracks 43 and 44,the wheels or rollers 48 and 49 being arranged to ride in tracks 43 and44 respectively. It will thus be understood that caterpillar brushsupporting plate 41 is mounted for limited movement along a lineparallel to the tracks 43 and 44.

Secured to the lower portion of supporting plate 38 are two bearings 50and 5I which are adapted to receive and have journalled therein sprocketaxles 52 and 53. Sprocket axles 52 and 53 each carry a pair of sprocketwheels 54 (see Figure 2) over which two endless articulated caterpillarbrush chains 55 ride. At the upper end of the assembly the two endlesschains 55 ride on sprocket wheels (not shown)' which are similar tosprocket wheels 54 and which are carried on a sprocket axle 56.

Since the position of the lower end of the caterpillar brush 29 is denedby the position of the axles 52 and 53, it will readily be perceivedthat the position of the lower end of caterpillar brush 29 depends uponthe relative position of the brush supporting plate 41 in thecomplementary tracks and 46.

Due to the relatively heavy weight of caterpillar brush 29, some meansmust be provided to partially relieve the weight of the brush, brushmechan-ism and brush fibres to lighten the pressure of the brushconstruction on the surface tobe swept. Such a means may be convenientlyprovided by counterbalancing the brush supporting plates 41. One meansfor providing such a counterbalance is shown in Figure 1, whereincounterweights 51 are provided on opposite sides of the vehicle II) andare pivotally supported from the chassis I3 by means of counterweightarms 58, the counterweight arms being pivotally mounted on the supportbrackets 55 at an intermediate point in their length as at 5i). Thecounterweight arms 5i' each have an overhanging portion 6I whichpivotally carries the supporting link arm 62. The lower end of the linkarm 62 is bolted or otherwise suitably secured to the supporting plate41 as at 53. As is clearly shown in Figure 1 of the drawings, the lowerend of each link arm 62 is preferably provided with a series of holes sothat the relative length of each link arm may be adjusted at the will ofthe operator of the machine. A position index may be provided byemploying an index scale 64 on the lower housing po-rtion 32 and apointer 55 on the plate 41.

From the above description it will be apparent that the greater part ofthe weight of the caterpillar brush 29 is released from the brush bres.The counterweights 51 are preferably adjusted on their arms 58 until theforce tending to lift the caterpillar brush 29 off of the streetapproaches but does not quite equal the weight which the brush bres ofthe brush 29 must support.

Previous mentioned has been made of the fact that lower housing portion32 is pivotally mounted for limited angular movement on upper housingportion I. Some means must of course be provided for limiting downwardmovement of the housing32 and for raising and lowering the same at-thewill of the operato-r. The means for raising housing 32 must includemeans for raising caterpillar brush 29 at the same time. Accordingly aflexible cable or chain 66 is provided for dening the lowermost positionof housing 32 which is connected at one end to the housing 32 as at 51and at the other end to the chassis I3 as at 68.`

Additional means is provided for raising and lowering the entirecaterpillar brushv assembly I If. More particularly, the caterpillarbrush 29 and the caterpillar brush lower housing 32 may be raised orlowered by means of a iiexible cable o-r chain 69 which branches offinto two lower chain portions 10 and 1I which are connected to thecaterpillar brush housing 32 and the caterpillar brush supporting plate41 respectively. The upper end of chain 69 is connected to a crank arm12 of a control lever 13 which is pivo-tally mounted on the chassis I3as at 14. Control lever 13 is preferably equipped with the usual springbiased latch (not shown) under the control of the control lever latchrelease 15, the latch being arranged to eng-age a cooperating notchedlatch plate 15 mounted on the side of the Vehicle. As shown in Figure 1of the drawings, when control lever 13 is in its forward position, thecaterpillar brush assembly I I is in its lowe-rmost position, while whencontrol lever 13 is in its rearwardmost position, the caterpillar brush29 and the caterpillar brush housing 32 have been lifted by the chain 63to a raised position.

A caterpillar brush tensioning device 'i1 is provided "to take up slackin the endless articulated chains 55 of the caterpillar brush assembly II and to provide the desired amount of tension therein. As will readilybe -appreciated from a cursory examination of Figure 1, the degree oftension in the endless chains 55 can be governed by varying the relativespacing of the upper sprocket axle 56 from the two lower sprocket axles52 and 53. Thus, if some means is provided for varyingthe distancebetween the upper sprocket axle 56 and the two sprocket axles 52 and 53,it is apparent that an adjustable tensioning arrangement will beprovided. The specific means for accomplishing this end has beendescribed in detail and claimed in my aforementioned copendingapplication Serial No. 207,446, led May 12, 1938, and assigned to thesame assignee as the present invention.

The tensioning device 11 is provided by journailing the upper sprocketaxle 59` in suitable bearings (not shown) carried on support plates 18which are arranged to slide within complementary flange or track members19 and 80. These complementary track members 19 and 80 are secured tothe side walls of upper housing 3| in parallel spaced relationship toeach other, but special note should be taken of the fact that thelongitudinal axis of the track members 19 and are not in parallelismwith the longitudinal axis of the track members 43 'and 44. While theangle of divergence of the longitudinal axis of the two sets of trackmay vary within wide limits without departing from the spirit and scopeof the present invention, the angle is illustrated in Figure 1 of thedrawings as being approximately 20, the lower ends of the track membersbeing further apart from each other than theirupper ends. Due to thefact that the longitudinal axis of the track members 19 and 30 isdisposed at an angle with respect to the longitudinal axis of trackmembers 43 and 44, it will readily be appreciated that by raising andlowering the support plates 18, the tension in the endless chains 55 maybe adjusted. This is by virtue of the fact that as the plate members 18are lowered in track members 19 and 80, the distance between the uppersprocket axle 56 and the two lower sprocket axles 52 and 53isvinc-reased. The position of the support plates 18 in the tracks 19and 85 is determinedY by clamping bolts 8l which are mounted in collars82 to upper housing 3|. f A position index is preferably employed byproviding an index scale 83 on the sides of the housing opposite eachlower track 19 and by providing a pointer 84 on the movable plate 18 ofeach tensioning device 11.

Power for driving the caterpillar brush 23 is obtained from the motor I4and is transferred through a pair of drive shafts 85 (the drive shaftsbeing illustrated in the drawings merely by showing the housing thereof)and then through a chain drive 86 to the upper sprocket axle 55, thenecessary drive chains 81 and sprocket wheels 88 and 89 being providedfor this purpose.

Power for driving the vehicle itself is obtained from the motor I4through a second pair of drive shafts 90, one on each side of thevehicle, and a pair of drive chains BI, the usual bevel gear boxes beingprovided at 92.

As may be ySeenbest in Figure 2 of the drawings, the caterpillar brush29 is preferably made up of a plurality-of individual brush units 93which are detachably and individually securedv to the articulatedchainsr 55. Each brush unit 93 includes in general a brush head 94 and abrush proper or bre portion 95, which is made up of a multitude ofindividual bres composed of any suitable material, such for example asbamboo fibres. The novel features and specific characteristics of thiscaterpillar brush and mounting are described in detail and claimedin mycopending application, Serial No. 216,740, led June 30, 1938, andassigned to the same assignee as the present invention.

During the sweeping operation the caterpillar brush 29 is driven in acounterclockwise direction from the upper sprocket axle 56. Theindividual brush units 93 as they pass over the surface being sweptcause the dirt and debris to be thrown forwardly and upwardly. In orderto convey the dirt and debris upwardly to a point where it may bedeposited in the hopper I2, an inclined plane 95 must be providedimmediately below the ends of the brush bres 95. his inclined plane 95forms the bottom wall of the brush housing portions 3| and 32, althoughit is spaced from the lower edges of the side walls of housing portions3| and 32.

In order to get the dirt and debris onto this inclined plane 96, it isnecessary to cause the lower end 97 of the inclined plane 96 to divergeslightly away from the brush libres 95 to provide a throat into whichthe dirt and debris may be thrown by the brushes. The upper portion 98of the inclined plane however is preferably in direct contact with thelower end of the brush fibres 95. This novel caterpillar brush and brushassembly is described in detail in my aforementioned co pendingapplication.

Extending downwardly from the lower edge of the inclined plane 96 andforming substantially a continuation thereof is a drag plate 99. For areason which will presently appear, drag plate 99 is mounted for limitedlongitudinal movement in a plane parallel to the lower end portion 9T ofthe inclined plane 96.

The particular mounting for the drag plate 99 may be seen best inFigures 3, 4, and 5, and includes a carriage having a pair of cross bars|0| and a pair of end bars |02. Rotatably mounted on each end bar |02 isa pair of flanged wheels |03. Housing 32 is suitably slotted at |04 forthe reception of wheels |03, the major axis of the slots |04 beingparallel to portion 91 of inclined plane 96. Welded or otherwisesuitably secured to the side walls of the housing 32 within slots |04are a set of tracks |05 in which the wheels |03 are arranged to ride.Two drag plate mounting arms |06 are secured to the underside of thedrag plate 99 by rivets |01 or in any other i suitable manner and thesemounting arms |06 are pivotally mounted to the carriage |00 as at |08. Astop arm |09, which is .arranged to engage lower cross bar lill, isprovided to prevent angular movement of the drag plate 99 below theplane of the portion 91 of the inclined plane 96. That is to say, whenthe carriage |00 is in its lowermost position, the drag plate 99 maymove angularlyupwardly, but cannot move angularly downwardly (seeFigures 3 and 6 of the draw* ings).

Now it has been found that in sweeping with a caterpillar brush, twoseparate and distinct problems must be overcome in order to have asatisfactory and eicient sweeping apparatus. particularly, it has beenfound that in order to sweep dirt and other finely divided debris thedrag plate 99 must be disposed relatively close to the surface beingswept. there is hardly any effective pickup by the caterpillar brush ofthe sweeping apparatus, for the reason that the dirt is swept forwardlyunderneath the drag plate. By way of example it was found that when thedrag plate was disposed with its lower edge approximately two inchesabove the More When this is not done,

surface being swept, there was little or no pickup ability left in thesweeping apparatus; but when the drag plate was disposed with its loweredge approximately three-quarters of an inch above the surface beingswept, the apparatus was very efficient in sweeping dirt.

If a drag plate is xed in this position, however, it has been found thatthe sweeping apparatus would not operate effectively to sweep up leavesand other debris of that character for the reason that the leaves wouldnot pass under the lower edge of the drag plate, but would cause them tobe pushed forwardly in front of it. Some means was necessary, therefore,to permit the leaves to pass to the caterpillar brush. One of theimportant featuresof the present invention is the manner in which thisis accomplished. More particularly, and in accordance with the teachingsof the present invention, the drag plate 99 is periodically oscillated(that is, raised) to permit the leaves and other similar debris to passthereunder to the caterpillar brush 29. In order to maintain effectiveand efficient sweeping of dirt and other nely divided debris, it hasbeen found preferable to provide a mechanism which will maintain thedrag plate 99 in its lowermost position for a predetermined distance andto then effect a quick lifting and lowering of the drag plate 99.

The novel means for periodically raising and lowering the drag plate 99includes a cam ||0 of the wiper 0r involute type (see Figures 2, 6 and7) which is centrally secured to a cam axle that is journalled inbearings |I2 and ||3 secured to one side wall of the housing 32 and to acentrally disposed mounting bracket I4 respectively. Secured to theouter end of the cam axle is a sprocket wheel |5 which is driven by anarticu-4 lated chain |6 from the drive shaft 85, a suitable gearreduction being provided in the gear box so that the rate of rotation ofthe cam ||0 is relatively slow. The speed of `rotation of cam I0 may, ofcourse, vary Within wide limits Without departing from the spirit andscope of the present invention, it being simply necessary to adjust thecam speed so that the accumulation of leaves and other similar debriswill not be unduly great.

The cam ||0 is positioned to engage a roller bar or cam follower IIBwhich is carried at the lower end of an L-shaped roller bar support arm||9. Roller bar support arm ||9 is centrally secured to the carrier |00,as may be seen best in Figures 2' and 4 of the drawings. From a carefulinspection of the drawings it will at once be understood that the cam||0 will cause an upward movement of the carrier |00 along its tracks|05 duringa small fraction of each revolution of the cam axle Thisupward movement of the carrier |00 causes the drag plate 99 to beperiodically raised in a plane parallel to the lower portion 91 of theinclined plane 95.

The drag plate 99 is pivotally mounted on the carrier |00 in order thatitmay pass over large stones |20 and other heavy objects without damageto the apparatus as is clearly shown in Figure 6.

To operate the sweeping apparatus of the present invention, power issupplied to the upper sprocket axle 56 which causes counterclockwisemovement of the endless chains which carry the brush units 93. Due tothe fact that the lower end of the caterpillar brush assembly 29 isfreely floating on the surface which is being swept, the lower ends ofthe brush bers are constantly in., engagement with this surface. By.properly adjusting the counterbalance weight 51, substantially all ofthe weight of the caterpillar brush assembly 29 is removed from thefibers 95 themselves. The individual brush units 93 sweep the dirt andother finely divided debris upwardly and forwardly against the dragplate 99 where it is carried by the brush 29 upwardly along the inclinedplane 96 until it passes over the open mouth |2| of the hopper I2.

Leaves and other debris of this character is pushed forwardly in frontof the drag plate 99 by the drag plate itself until the drag plate israised by the cam I|0 in the manner shown in Figure 7 of the drawings.other debris of this character pass under the lower edge of the dragplate 99 where they are thereafter swept forwardly and upwardly by thebrush units 93 onto the inclined plane 99.

AS the rotation of the cam I I9 is continued, the drag plate 99 lsreturned by gravity or by suitable spring means (not shown) to itslowermost posi- `tion as shown in Figure 2 where it is again effectiveto catch and collect the dirt swept forwardly and upwardly by theindividual brush units 93. During the interval that the drag plate isbeing moved upwardly and returned, the dirt and nely divided debris onthe surface being swept is merely thrown forwardly ahead of the brushesuntil such a time as the drag plate is in its lowermost position, wherethe dirt and other finely divided debris is again caught and collectedby the drag plate and caused to pass upwardly along the inclined plane96 into the hopper I2.

Thedirt shoes 31 slide along the surface which is being swept andprevent dirt and other debris from slipping out either side of thesweeping apparatus. These dirt shoes 3| thus prevent any impairment ofefficient sweeping action by the apparatus.

After the storage hopper I2 has become filled, the dirt and debriscollected therein may be dumped by throwing the dump lever 21 upwardlyand forwardly thus causing the lower end wall 2 2' of the hopper I2 toopen about its pivot 24. After the hopper I2 has been dumped, the endwall 22 is returned to its closed position by pulling the dump leverbackwardly and downwardly until it has passed its overcenter position.

In traveling to and vfrom the area to be swept, the caterpillar brushassembly 29 and the lower brush housing 32 are elevated by pulling thecontrol lever 'I3 to its rearward position (that is, to its left handposition as viewed in Figure 1 of the drawings).

From the above description Vit will be apparent that I have illustratednovel means for carrying out a novel method of cleaning streets. As willreadily be apparent -to those skilled in the art, dirt and finelydivided debris is segregated from other debris such as leaves and thelike. The dirt and finely divided `debris is continually permitted topass to the brush of the sweeping apparatus while theother debris, suchas leaves, is pushed forwardly, except for intermittent intervals, whenit is permitted to pass to the sweeping brush along with the dirt andnely divided debris. This novel method may obviously be carried out bymany different types of apparatus and for that reason is independent ofany specific apparatus.

The novel apparatus which has been illustrated as being one form ofapparatus capable of carrying the novel method described herein isdescribed and claimed in another copending appli- At this time leavesand cation Serial No. 207,445, filed May l2, 1938, and assigned to thesame assignee as the present invention.

My novel method may, of course, be carried out by many other forms ofapparatus, two forms of which will now be described. y

Figure 8 illustrates a sweeping apparatus of the rotary brush beltconveyor type. For purposes of simplicity, only the essential elementsof the sweeping apparatus which relate to the novel method of t-hepresent invention have been illustrated, but it is to be understood thatthis apparatus is, of course, mounted on a suitable sweeping apparatusvehicle, such as the one illustrated in Figure l, which includes astorage hopper having an open mouth disposed beneath the top of the beltconveyor, the brush and belt conveyor and other associated mechanismsbeing driven from a suitable power supply source.

Referring now to Figure 8, there is illustrated therein a rotary brush|22, a belt conveyor |23, and a drag -plate |24. rIhe belt conveyor |23is provided with a plurality of transversely disposed raised portions orT-bars which are designed to retain dirt and other debris which isthrown onto the belt conveyor |23 by counterclockwise rotation of therotary brush |22. The belt conveyor |23 extends forwardly and upwardlyfrom a point in front of the rotary brush |22 and slightly above thesurface |26 which is being swept. It is to be understood that thelowermost point |21 of the belt conveyor |23 is spaced at a suicientdistance above the surface |25 to permit all forms of debris which areadapted to -be swept up by the sweeping apparatus to pass thereunder.

The drag plate |24 is mounted on a carriage |23 which is suspended fromthe vehicle in such a manner as to permit limited movement of the dragplate |24 in a plane parallel to the upper surface of the belt conveyor|23. While the particular manner in which the carriage |28 is mounted onthe vehicle has not been shown for purposes of simplicity ofillustration, it is to be understood that this may be mounted in anyconvenient manner, such, for example, as that lshown in connection withFigures l to 7 of the drawings. Connected to the upper end of thecarriage |28 is an L-shaped member |29 which is provided with a rollerbar |39 at its outer extremity. Roller bar |39 is adapted to be engagedby an involute type cam |3| in a manner similar to that described inconnection with Figures 1 to 7, it being understood that the cam I 3| isrotated in a counterclockwise direction by forward movement of thevehicle, thereby causing intermittent raising and lowering of the dragplate |24 at a predetermined distance of travel of the sweeping apjwhich are adapted to be swept up by the apparatus are thrown forwardlyand upwardly by centrifugal force and onto the belt conveyor |23, whereit is carried upwardly into the storage hopper (not shown). If the dragplate |24 is` not provided, it has been found that leaves and othersimilar debris will be swept up by the sweeping apparatus, but dirt andother nely divided debris is not swept eiiiciently, by reason of thefact that a great part of it is thrown forwardly under the lower edge ofthe belt conveyor |23. Drag plate |24 or some other similar form ofpickup plate is therefore necessary to provide efficient sweeping ofdirt and other nely divided debris. If the drag plate is notperiodically raised and lowered, as was previously pointed out, theleaves and other debris of this character would never reach the brush.The drag plate |24 therefore acts as a means for segregating dirt andother finely divided debris from leaves and other similar debris, andfurther provides a means for continually passing nely divided debris tothe brush but permitting a passage of leaves and other similar debris atperiodic intervals only.

A third form of apparatus capable of carrying out the novel method ofthe present invention is illustrated in Figure 9 of the drawings. Inorder to simplify the illustration as much as possible, only thatportion of the sweeping apparatus which directly bears upon the novelmethod has been illustrated. As shown, the sweeping apparatus includes acaterpillar brush |32, an inclined plane |33, the lower portion |34 ofwhich dlverges slightly outwardly away from the bottom of thecaterpillar brush |32 `to provide a. debris receiving throat |35, and adebris segregating and collecting means |36, the debris segregating andcollecting means |36 is provided with four transversely disposed plates|31, which are placed substantially at right angles to each other. Thesegregating and collecting means |35 is arranged to be periodicallyrotated in a clockwise direction through `an angle of substantially 90.In other words, one of the transversely disposed plates |31 is adaptedto be moved into the position previously occupied by the next succeedingplate |31 at intermittent intervals, one of the plates |31 during theintervals between rotation always being in a downwardly extendingposition. The lower edge of the segregating and collecting means |36 isso spaced above the surface which is being swept, that the dirt andother finely divided debris is permitted to pass thereunder, but leavesand other similar debris are pushed forwardly thereby. By rotating themeans |36 through 90 in a clockwise direction, it will at once beapparent to those skilled in the art that the leaves and other debriswhich have been collected in front of the means is permitted to pass tothe caterpillar brush |32; as the next succeeding plate |31 moves into adownwardly extending position, further passage of leaves and othersimilar debris is prevented and the means thereafter acts as asegregating and collecting device, the leaves being pushed forwardlythereby.

The segregating and collecting means |36 may be periodically rotated inany suitable manner, the particular means shown in Figure 9 being a rack|38 and a ratchet wheel |39. The ratchet wheel |39 is secured to thesegregating and collecting device |36, while the rack |38 is slidablymounted on the side wall |40 of the sweeping apparatus by a pin and`slot connection |4| and |42 respectively. The pin |4| has mountedthereon an involute type cam |43 which is arranged to be rotated by theforward movement of the sweeping apparatus. Mounted on the end of therack |38 is a roller bar |44 which engages the cam |43.

From the above description it will be seen that I have provided anextremely simple and yet elicient method of sweeping and cleaningstreets and other surfaces, and which permits the use of apparatus whichis economical to manufacture and which is rugged and reliable in use.

While I have illustrated a street sweeping apparatus with a rear mountedmotor and a front mounted dirt andclebris collecting hopper, it will, ofcourse, be understood that the same vehicle can be run in the oppositedirection with all of the equipment disposed in exactly the sameposition as that illustrated in the drawings, it being simply necessaryto increase the speed of the caterpillar brush to a speed at which theground speed of the brush fibres is substantially greater than theground speed of the vehicle (such, for example, as twice the groundspeed). This increase in the speed of operation of the caterpillar brushis necessary when the vehicle is being moved in the opposite directionin order to obtain an effective relative rearward speed of thecaterpillar brush with respect to the surface being swept which isnecessary to cause the dirt and debris to be thrown rearwardly onto theinclined plane which is now located behind the brush rather than infront of the brush as is the case when the machine is being moved in thedirection indicated in the preferred embodiment of the invention.

While I have designated my sweeper as a street sweeper, it is, ofcourse, to be understoodthat I do not intend in the accompanying claimto limit the use of my sweeper solely for cleaning streets. It may beused with equal advantage in sweeping paved yards, warehouse oors,stadium floors, and numerous other similar surfaces where extensivesweeping operations are required.

While I have shown particular embodiments of my invention, it will, ofcourse, be understood that I do not Wish to be limited thereto, sincemany modifications may be made, and I therefore contemplate by theappended claim to cover all such modifications as fall within the truespirit and scope of my invention.

I claim as my invention:

The method of sweeping and brushing a surface such for example as thatof a street which comprises continuously brushing the dirt and dust offthe surface in a predetermined confined sweeping Zone both as thesurface is being forwardly traversed and also when the sweeping isconned only to a given portion of the surface without any forwardmovement thereover, contemporaneously with forward movement over thesurface scraping together debris other than dust and dirt such as`leaves, twigs and refuse and the like so as to collect such debris inadvance of the sweeping zone, periodically releasing the debris scrapedtogether so as to allow the same to enter the confined sweeping zone asthe surface being swept is forwardly traversed and thereafter sweepingup in said conned zone such segregated and collected debris olf saidsurface.

' RONALD CLEMENT EVANS.

